How black holes grow

The earliest black holes to form will be much bigger today

Giant star

The first generation of very massive stars, hundreds of times as massive as the Sun, would have burnt through their nuclear fuel very quickly.

Seed black hole

These stars collapsed down to black holes of tens of solar masses, which then acted as seeds for the creation of much larger black holes.

Accretion

Over billions of years, gas and dust spiralling into these black holes increased their mass; this isn’t enough to explain supermassive black holes.